In a press conference at the White House, Trump said he didn't say he "hoped" Comey, whom Trump fired on May 9, would "let go" of an investigation into former national security adviser Michael Flynn. Comey has said Trump asked him in a private meeting in February to end that probe.

But Trump added that if he had made those comments, there would be nothing wrong with it, "according to everybody that I read today."

Trump, speaking alongside Romanian President Klaus Iohannis in the Rose Garden, also said he was "100%" willing to testify under oath to dispute claims Comey made before the Senate committee.

"I didn't say that," Trump said of Comey's assertion. "And there'd be nothing wrong with it if I did say that, according to everybody that I read today, but I did not say that."

Trump did not make clear what he had read. Earlier Friday, he retweeted a post from Alan Dershowitz, a prominent lawyer and Harvard professor, who said there was "no plausible case" for obstruction of justice and that "we must distinguish crimes from" political "sins."

Comey also said in his testimony that Trump asked for his "loyalty" during a dinner in January, but Trump insisted this was also untrue.

"I hardly know the man," Trump said. "I'm not going to say, 'I want you to pledge allegiance.' Who would do that? Who would ask a man to pledge allegiance under oath? I mean, think of it, I hardly know the man. It doesn't make sense. No, I didn't say that. And I didn't say the other."

Trump added that he "would be glad" to tell Robert Mueller, the special counsel who is overseeing the FBI's investigation into Russia's election meddling and whether Trump's campaign played a role, "exactly what I just told you," but under oath.

Earlier Friday, Trump tweeted that Comey's testimony was a "total and complete vindication" for him "despite so many false statements and lies."

He explained in the press conference why he felt vindicated by the testimony:

"No collusion. No obstruction. He's a leaker. But we want to get back to running our great country. Jobs, trade deficits — we want them to disappear fast. North Korea, big problem. Middle East, a big problem. So that's what I am focused on. That's what I have been focused on. But yesterday showed no collusion, no obstruction. We are doing really well. That was an excuse by the Democrats, who lost an election that some people think they shouldn't have lost.

"Because it's almost impossible for the Democrats to lose the Electoral College. You have to run up the whole East Coast, and you have to win everything as a Republican, and that's what we did. So it was just an excuse, but we were very, very happy. And frankly, James Comey confirmed a lot of what I said. And some of the things he said just weren't true."

Trump also addressed whether any tapes of his conversations with Comey existed.

Trump's tweet in May that Comey had "better hope that there are no 'tapes'" drove Comey to instruct a good friend, a Columbia University law professor, to leak information on his memos of his conversations with the president to the media, Comey said. He said he did this because he felt the investigation may have reached a point at which a special counsel needed to be appointed.

Trump and his outside attorney, Marc Kasowitz, have zeroed in on this and lambasted Comey for ordering the "leaks."

During his Thursday testimony, Comey said he hoped Trump would produce the tapes if he had them.

On Friday, Trump said on three occasions that the media would soon know about whether tapes existed.

"Well, I'll tell you about that maybe sometime in the very near future," he said, later adding that he was "not hinting anything" about whether there were any tape-recorded conversations.

"I will tell you about it over a fairly short period of time," he said. "You're going to be very disappointed when you hear the answer."

James Comey. AP

Comey's testimony provided several bruising moments for Trump. Comey said he believed he was fired "because of the Russia investigation," amplifying calls that Trump obstructed justice. He also said he took Trump's comments about the Flynn probe "as a direction."

Comey said he kept memos on his conversations with Trump — but hadn't with two previous presidents or other top Justice Department officials — because he "was honestly concerned that he might lie about the nature of our meeting."

Comey also said Trump and his administration tried to "defame" him by spreading "lies, plain and simple," about his firing. He cited Trump's "shifting explanations," which he said included Trump saying on TV "that he actually fired me because of the Russia investigation."

But Comey did not provide any proverbial smoking gun.

As FBI director, Comey oversaw the bureau's investigation into whether the Trump campaign colluded with Russian officials to interfere in the 2016 presidential election.

Some top Democrats — including Sens. Chris Murphy of Connecticut, Brian Schatz of Hawaii, and Chris Van Hollen of Maryland — had already started to call for Trump to testify under oath before Trump brought it up on Friday.

"I called on him to do this yesterday," Murphy tweeted after Trump's press conference. "Now, let's make it happen. Senate can send over the invite ASAP."